February 14, 2011

You say Me-Moh, I say My-Moh

MIMO, the acronym meaning Multiple Input/Multiple Output, is an integral aspect of 802.11n wireless networking. The terminology, regardless of how you choose to pronounce it, is more than a geeky tech term. In fact, MIMO operation has a direct bearing on the performance of a wireless network and the ability of an access point to provide coverage.

While some vendors and analysts are quick to dismiss its relevance, they fail to arm customers with important knowledge on its functionality. With MIMO, an access point has the power to simultaneously transmit and receive traffic across its antennas. The capability means that a given access point can communicate with an end station across multiple paths, with optimization and path selection changing as required. To achieve optimized pathing, the radio signals are reflected off surfaces such as floors, ceilings and walls. Ultimately, having more than one signal path to choose from allows the access point and end stations to transmit/receive at greater ranges with better signal strength and faster speeds.

An access point equipped with 2×2 MIMO operation can send and receive across two paths. If one of those paths is blocked, congested, interfered with, or has become unavailable, the client is left with one path back to the access point. This will adversely affect communication potentially degrading to legacy data rates. Alternatively, an access point with 3×3 MIMO operation offers a third path between the access point and end station. In this sense, the AP has one additional path to use thereby providing greater assurance of range and coverage.

If you think of it in terms of resiliency, that third path will fill coverage gaps while ensuring the end station is communicating at the highest possible data rates at all times. Move the concept into the real world where the number of clients is more than one, and you will quickly see the impact that MIMO has. Translated by one noted radio manufacturer, wireless environments can experience upwards of 40% greater performance and coverage with 3×3 vs. 2×2 MIMO.

When choosing a vendor and selecting .11n access points, you should review and understand what you are buying. Like most things in life, you get what you pay for and there are trade-offs. If you seek low cost options you might live with a lower performing .11n network.

So whether you choose to say Me-Moh or My-Moh, now that we’ve straightened a few things out, don’t be in such a hurry to call the whole thing off.

About The Contributor:
Scott FergusonWireless Product Marketing Manager

Scott Ferguson is a Product Marketing Manager at Extreme Networks with 20+ years of domestic and international experience in the computer and data communications industry. He has held numerous senior level positions in engineering, product management, and product marketing for start-ups, fortune 500 companies, and business turnarounds in both carrier and enterprise focused businesses. Scott is an industry leader driving hardware and software products to financial success and market recognition, in: security, management systems, network infrastructure, and applications. Scott has held senior level positions at companies that include Apani Networks, Avaya, Colubris Networks, Nortel Networks, and Xyplex Networks. Scott has also been a consultant for companies helping them achieve their business goals through his strategic / business planning, new product introduction, implementation, and marketing skills.

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